Cause of Problem?

[jfls41]

Situation: detached garage with underground cable coming in no disconnect, just a junction box. It is fed from part of the unfinished basement lighting circuit which has armoured cable. It then goes into homeowners newly remodeled basement office which is finished with no access points to where the underground feed leaves the basement to the garage. The problem? Getting 121 volts across the neutral and bare ground wire in the garage and the exposed armoured cable in the basement I get 121 volt reading neutral to ground. The ground and the netrual is bonded together in the panel box. The armoured cable is clamped into the panel box properly. The rest of the circuits are new romex and properly grounded. What could be causing ground fault? Could inadequate grounding or bonding from the panel box allow this to happen? I would like to hear how others handled this problem? One thing I did notice and I used to different meters when checking to make sure, when I first touched my probes to get a reading, it quickly went to 240 something volts for a split second and then dropped down to 121v.

 

[luke warmwater]

Re: Cause of Problem?

Maybe somewhere along the circut, someone reversed the hot and neutral.

The hot could have gotten shorted and someone swapped the black and white.
This is a common find in knob and tube wiring where metal lath is involved.

Did you turn the breaker(?fuse) off and check for continuity between anything?


You were probably using a digital meter, hence the 240 thing. I would disregard that if it was a digital meter.
Leave the probes contacted for a few seconds for an accurate reading.

 

[jimwalker]

Re: Cause of Problem?

You might have an open neutral between point your measuring at and the panel.The reading may be going thru the load.Can we assume nothing is working in the garage ? As a back up test try using a load where your checking at or a wiggy.